<script lang="ts" setup name="XtxCarousel">
import { BannerItem } from '@/types/data'
import { onMounted, onUnmounted, ref } from 'vue';
// 不要在组件内部获取数据渲染
// vue3
// defineProps({
//     slices: {
//         type: Array,
//         required: true
//     }
// })

// vue3+ts
const { slides, duration = 1000, autoplay = false } = defineProps<{
    slides: BannerItem[],
    duration?: number
    autoplay?: boolean
}>()

// 声明变量初始化图片及小圆点的值
const active = ref(0)

// 1.点击小圆点实现图片切换
// 2.点击上下一张实现图片切换
// 上一张
const prev = () => {
    active.value--
    if (active.value < 0) {
        active.value = slides.length - 1
    }
}
// 下一张
const next = () => {
    active.value++
    if (active.value > slides.length - 1) {
        active.value = 0
    }
}
// 3.自动轮播
// 注意1:当组件挂载完毕时,再开启定时器,关闭(销毁)组件时,关闭定时器
// 注意2:setInerval是node中的setInerval,如果想用加window
let timer = -1
onMounted(() => {
    // timer = window.setInterval(() => {
    //     next()
    // }, 1000)

    start()
})

onUnmounted(() => {
    // clearInterval(timer)
    stop()
})

// 4.进入轮播图停止自动播入,离开时再开启轮播图
const stop = () => {
    clearInterval(timer)
}

const start = () => {
    if (!autoplay) return
    timer = window.setInterval(() => {
        next()
    }, duration)
}


</script>

<template>
    <div class="xtx-carousel" @mouseenter="stop" @mouseleave="start">
        <!-- 轮播图图片 -->
        <ul class="carousel-body">

            <li class="carousel-item" :class="{ fade: active === index }" v-for="(item, index) in slides"
                :key="item.id">
                <RouterLink :to="item.hrefUrl">
                    <img :src="item.imgUrl" />
                </RouterLink>
            </li>

        </ul>
        <!-- 上一张 -->
        <a href="javascript:;" class="carousel-btn prev"><i class="iconfont icon-angle-left" @click="prev"></i></a>
        <!-- 下一张 -->
        <a href="javascript:;" class="carousel-btn next"><i class="iconfont icon-angle-right" @click="next"></i></a>
        <!-- 小圆点 -->
        <div class="carousel-indicator">
            <span @click="active=index" :class="{ active: active === index }" v-for="(item, index) in slides"
                :key="item.id"></span>
        </div>
    </div>
</template>

<style scoped lang="less">
.xtx-carousel {
    width: 100%;
    height: 100%;
    min-width: 300px;
    min-height: 150px;
    position: relative;

    .carousel {
        &-body {
            width: 100%;
            height: 100%;
        }

        &-item {
            width: 100%;
            height: 100%;
            position: absolute;
            left: 0;
            top: 0;
            opacity: 0;
            transition: opacity 0.5s linear;

            &.fade {
                opacity: 1;
                z-index: 1;
            }

            img {
                width: 100%;
                height: 100%;
            }
        }

        &-indicator {
            position: absolute;
            left: 0;
            bottom: 20px;
            z-index: 2;
            width: 100%;
            text-align: center;

            span {
                display: inline-block;
                width: 12px;
                height: 12px;
                background: rgba(0, 0, 0, 0.2);
                border-radius: 50%;
                cursor: pointer;

                ~span {
                    margin-left: 12px;
                }

                &.active {
                    background: #fff;
                }
            }
        }

        &-btn {
            width: 44px;
            height: 44px;
            background: rgba(0, 0, 0, 0.2);
            color: #fff;
            border-radius: 50%;
            position: absolute;
            top: 228px;
            z-index: 2;
            text-align: center;
            line-height: 44px;
            opacity: 0;
            transition: all 0.5s;

            &.prev {
                left: 20px;
            }

            &.next {
                right: 20px;
            }
        }
    }

    &:hover {
        .carousel-btn {
            opacity: 1;
        }
    }
}
</style>